Those skilled in the art know that some vehicles, such as trucks, farm vehicles, and heavy duty construction vehicles, have wheels that are driven by hydraulic drive motors located at the wheels. Typically, each wheel end has a knuckle that utilizes a plurality of large hydraulic fittings that function as supply, return and drain ports. The ports are typically located all about the knuckle. Hoses, which are connected to these fittings at these locations, are required to traverse a large arc when the axle is steered. Such an arrangement of fittings and hoses, however, is difficult to package within the vehicle and uses large amounts of hose material.
A few examples of methods of providing fluid to a hydraulically driven wheel include devices described in the following patents. U.S. Pat. No. 4,171,732 discloses a fluid supply port on an upper surface of an inboard portion of a knuckle. The fluid return port, however, is located on a lower surface of the inboard portion. This design causes significant problems in packaging the hoses attached to these ports. Additionally, the fluid return hose, being located below the spindle, is highly susceptible to damage from items on the ground and from the ground itself.
U.S. Pat. No. 3,612,204 teaches a rigid fluid supply and return lines fixedly attached to an upper portion of a boss. The motor may pivot about the boss to provide steering to a wheel. As can be appreciated by FIG. 7 of this patent, the fixed fluid lines take up a tremendous amount of space at the wheel end.
U.S. Pat. No. 4,111,618 discloses supply and return lines all entering the spindle substantially parallel with the spindle centerline. The supply lines are located above/below the drain line, the drain line is at the centerline. All fluid lines are arranged about the centerline of the spindle and enter the spindle at this point as well.
As can be appreciated from the above discussion, some designs require a large amount of hose material and require that the fluid hoses traverse a large arc when the axle steers, which is difficult to package. Thus, a vehicle having hydraulic hoses connected to a wheel end having a hydraulic motor disposed thereon, may benefit from an arrangement of hydraulic hoses that does not require a large amount of hose material and does not require a wide arc for the hoses to traverse when the wheel end is steered in various directions. Such an arrangement would be less expensive to produce, easier to package, more robust, allow for faster steering reaction, and would be more easily connectable at the time of assembly of the vehicle.